This invention relates to a method of treating hair by applying thereto certain amine carboxylate zwitterionomeric polysiloxanes which have been found to impart conditioning benefits to hair.
Hair preparations are compositions which are employed on the scalp or hair. The most important hair preparations are shampoos, conditioning products, colorants, hairstyling preparations including setting lotions and hairsprays, and permanent wave preparations.
Shampoos are mild cosmetic products for cleaning the hair and scalp. Hair becomes soiled due to skin flakes, sebum, perspiration, dust, and residues from sprays, lotions and conditioning agents. Shampoos are designed to leave the hair clean, pliable, lustrous, possessing a pleasant odor, and easy to untangle, comb, manage, and style. The principal ingredient of a shampoo is a surfactant which functions to release dirt from the hair and to transport it to the aqueous Since consumers equate lathering with cleanliness, anionic surfactants such as alkyl sulfates and sulfonates are preferred because of their high lather. Numerous other constituents are included in shampoos such as thickeners to prevent the shampoo from running down the face into the eyes, opacifiers to provide a rich pleasing pearlescent appearance, buffers to adjust the pH of the shampoo to a value which is gentle to the skin, and fragrances to impart a pleasant aroma to the washed hair following rinsing. Most frequently, shampoos are marketed as clear products although gels having a higher viscosity and packaged in tubes, and pearlescent compositions are available. Exemplary shampoo formulations are described in detail in U.S. Pat. No. 4,364,837 issued Dec. 21, 1982; U.S. Pat. No. 4,704,272 issued Nov. 3, 1987; and U.S. Pat. No. 4,741,855 issued May 3, 1988.
With the advent of consumer trends toward daily hair washing, conditioning shampoos have emerged which are designed to render the hair easy to comb and tangle free in the wet state, as well as glossy and soft when dry. Such conditioning is provided by cationic polymers which upon rinsing produce a thin film on the hair. This film functions as a lubricant when the hair is wet and prevents static charge and "flyaway" when the hair is dry. Conditioning shampoos are described in U.S. Pat. No. 4,559,227 issued Dec. 17, 1985 and U.S. Pat. No. 4,777,037 issued Oct. 11, 1988.
Conditioning may also be provided by hair conditioning products designed solely for that purpose such as rinses, mousses, aerosols, and pump sprays, which conditioners are applied following shampooing. These conditioning products are rinsed from the hair a short time following their application. Such conditioners prevent excessive split ends and other mechanical hair damage and roughening, and seek to neutralize the adverse effects which hair undergoes due to humidity, temperature, exposure to sunlight, frequent washing, combing, and brushing, and cosmetic treatments such as bleaching, dyeing, and waving. Examples of these products can be found in U.S. Pat. No. 4,387,090 issued Jun. 7, 1983; U.S. Pat. No. 4,563,347 issued Jan. 7, 1986; and U.S. Pat. No. 4,954,335 issued Sep. 4, 1990.
Styling preparations are not rinsed out and remain in the hair. Such preparations contain film forming agents such as vinylpyrrolidone polymers and copolymers which are designed to stabilize the hairstyle during and following its creation with a comb, brush, or rollers. Setting lotions for temporary sets are applied to the hair after it has been washed and towel dried. The hair is then wound on rollers and dried. Setting lotions for blow drying are similarly applied but the hair is brushed and combed while being dried with a hair dryer. Stabilization of the hairstyle is achieved by stiffening and increased friction between hairs. These lotions are marketed as thin aqueous alcohol solutions, aerosol sprays, pump sprays, and aerosol foam mousses. Various hair setting formulations are set forth in U.S. Pat. No. 4,724,851 issued Feb. 16, 1988; U.S. Pat. No. 4,733,677 issued Mar. 29, 1988; and U.S. Pat. No. 4,834,968 issued May 30, 1989.
Hairsprays are used to protect the hair from wind and humidity. Such sprays should dry quickly and be easily removable by brushing and washing without generating a visible dust. The hair must have a pleasant smell, be glossy, and not feel dull following application. Typically, these formulations are marketed as two phase aerosols containing a film forming agent, a solvent, and a propellant. Ethanol is the preferred solvent, and since 1979 alternative hydrocarbon propellants such as propane, butane, isobutane, pentane, and dimethylether have replaced the chlorofluorocarbons. Packaging is an important aspect of hairsprays and metal containers having an inner coating of lacquer are required. The valve and nozzle selection for the container is crucial for provision of a proper spray pattern. More recent novel hairstyling preparations include setting gel fixatives which are thickened solutions and microemulsions containing film forming agents which provide for the creation of the "wetlook" hairstyle. Examples of hairspray products are described in U.S. Pat. No. 3,928,558 issued Dec. 23, 1975 and U.S. Pat. No. 4,871,529 issued Oct. 3, 1989.
The amine carboxylate zwitterionomeric polysiloxanes of the present invention may be employed in any of the foregoing hair treatment preparations for the purpose of imparting conditioning benefits. In addition to conditioning, it has been unexpectedly discovered that these zwitterionomers provide a body effect to the hair rendering it springy and bouncy. This is significant since known hair bodying agents are resins whereas the zwitterionomers of the present invention are fluids capable of forming elastomeric films.
While it is known to apply organosilicon ionomeric compounds to hair as shown in U.S. Pat. No. 4,609,750 issued Sep. 2, 1986, the amine carboxylate zwitterionomeric polysiloxanes of the present invention differ significantly from these betaines of the prior art.
For example, the ionomers of the present invention are ammonium carboxylate ionomers whereas the ionomers of the '750 patent are permanent quaternary amine carboxylate ionomers. Thus, the nitrogen atom in the '750 patent is always positively charged. Because of this permanent positive charge and because there are no hydrogen atoms bonded to the cationic site in the '750 patent as in the ionomers of the present invention, it is possible to form a multiplicity of structures with the ionomers of the present invention. In addition to the pure ionomer, the present invention provides for the formation of conjugate acid base pairs of the ionomer with either an acid or a base. Both pairs are not possible with the ionomers of the '750 patent.
An additional distinction between the ionomers of the present invention and the ionomers of the '750 patent is that the ionomers of the '750 patent are betaines and not amino acids, whereas the ionomers of the present invention can be appropriately classifiable as silicone functional amino acids. Finally, the order of arrangement of the amide linkage, the positive charge, and the negative charge, in the Q group of the '750 patent and the present invention is not the same. Specifically, the order of the positive charge and the amide linkage in these Q groups is reversed.